So this is what we learn:
It's absolutely okay to start eyeing your best friend's husband, even if she's more like a sister and her family has lovingly treated you like their own.
It's perfectly fine to take that friend's help to get out of a bad situation and then sideline her in her own house when you suck up to the centre of power, BQ, and her chamchis, who clearly show their dislike/hatred of your friend.
Of course it's no big deal to start resenting said friend for 'snatching' the guy you never even wanted and letting yourself be persuaded you deserve him and the life he would offer, ignoring all your friend's deeds in that position, which you would never do. Easy-peasy, just go for the kill, even literally.
Treat friend with contempt, ignore her tears and confusion at your behaviour, plot against her, call her names, act all superior.
Tell her husband, effectively your brother-in-law you love him, even when your friend has just confided that she wants to say the magic words. Drape yourself over him in the most disgusting manner and think you are too seductive to resist.
Under BQ's tutelage, start a series of off-putting actions ranging from persistently pursuing effective brother-in-law IN SPITE OF HIS DISLIKE OF YOUR MOVES, putting down ex-bestie, convincing yourself you're right. And one of these game-playing moves causes your friend to narrowly get away from a rape attempt, which leaves you unmoved, but you react when she hugs her husband (your future bank) seeking comfort.
WITHOUT any tutoring from BQ or chamchis, sending your friend to die, before fear and an attack of conscience makes you run to her rescue. Use your 'rescue' to change tactics and befriend your target and set up circumstances where you use this to inveigle the poor fool hubby into your trap while driving a wedge of suspicion between him and wife--your saviour, remember? Show no compassion or affection, just self-interest.
When your friend finally catches on and confronts you, blame it on BQ. No remorse, nothing.
After ALL this culminating in the now brain-dead friend apparently planning your wedding to her husband, act like it's so par for the course and nothing more than your due, until you suddenly decide that if your ex is interested in someone else, maybe you want him too.
Drag marriage charade to the mandap, get sudden attack of love for ex-hubby, marry him, and have the 2 fools you sent spinning to the edge officiating, accepting your (bound to be) absolutely unbelievable 'apology' and sending you off with their blessings.
Nauso chuhe kha ke billi haj ko chali.